Synchronous Image-Label Diffusion Probability Model with Application to Stroke Lesion Segmentation on Non-contrast CT

Stroke lesion volume is a key radiologic measurement for assessing the prognosis of Acute Ischemic Stroke (AIS) patients, which is challenging to be automatically measured on Non-Contrast CT (NCCT) scans. Recent diffusion probabilistic models have shown potentials of being used for image segmentation. In this paper, a novel Synchronous image-label Diffusion Probability Model (SDPM) is proposed for stroke lesion segmentation on NCCT using Markov diffusion process. The proposed SDPM is fully based on a Latent Variable Model (LVM), offering a complete probabilistic elaboration. An additional net-stream, parallel with a noise prediction stream, is introduced to obtain initial noisy label estimates for efficiently inferring the final labels. By optimizing the specified variational boundaries, the trained model can infer multiple label estimates for reference given the input images with noises. The proposed model was assessed on three stroke lesion datasets including one public and two private datasets. Compared to several U-net and transformer-based segmentation methods, our proposed SDPM model is able to achieve state-of-the-art performance. The code is publicly available

The exploration of upconversion luminescence nanoprobes for tobramycin detection based on Förster resonance energy transfer

Tobramycin (TOB) is a broad-spectrum aminoglycoside extensively used as veterinary medicine to treat bacterial infections. However, TOB residue in food and environment may cause great threat to human health. Here, we report, for the first time, the upconversion nanoparticles (UCNPs) for TOB detection based on Förster resonance energy transfer (FRET). The upconversion (UC) luminescence from core-shell structured UCNPs was effectively quenched after addition of MnO2 nanosheets due to the efficient energy transfer from the UCNPs to MnO2 nanosheets. When interacting with TOB, the UC luminescence was restored and increased as a result of coupling between TOB and aptamer, with MnO2 nanosheets dropping off the latter one. The UCNPs@SiO2-MnO2 aptasensors for TOB detection have a good selectivity and sensitivity in a linear range of 10–180 ng mL−1 with a limit of detection (LOD) of 3.04 ng mL−1. The sensors were tested for TOB detection in real samples of liquid milk and fishes and the results are very good and satisfactory. These type of aptasensors are promising for practical applications as they have a high sensitivity, selectivity, low LOD, and are autofluorescence-free

ERβ modulation and non-modulation of ERα by administration of geniposide and panax notoginseng saponins in SH-SY5Y cells

Objective: To illustrate the effect of geniposide (GP) and panax notoginseng saponins (PNS) on estrogen receptors (ER) including ERα and ERβ within the cytoplasm and nucleus of SH-SY5Y cells. Methods: Immunofluorescence was used to observe the distribution of ERα and ERβ in cytoplasm and nucleus, but Western blot was only for ERβ detection. q-PCR was applied to detect NR3C1, S100A6 and LGALS1downstream mRNA gene expression levels of ER. Results: Through analyzing fluorescence intensity under the administration of GP and PNS in SH-SY5Y cells, we found that the distribution of ERα has not been affected. We also discovered that GP and/or PNS significantly stimulated the transportation of ERβ into the nucleus in a time-dependent manner (all P < .001). When SH-SY5Y cells were treated with supplements of GP, PNS, GP + PNS at 15 minutes, 30 minutes and 45 minutes, the distribution of ERβ in the nucleus significantly increased compared with that in control group (all P < .001). Evidently, treatment with GP, PNS, GP + PNS was able to significantly increase the levels of ERβ protein within the nucleus compared with control group at both 30 minutes and 45 minutes intervals (all P < .001). Furthermore, GP and PNS showed signs of activating to NR3C1 and LGALS1, two genes downstream of ER. It is possible that the S100A6 gene mainly encoded the downstream gene in ERα's signaling pathway, which was not affected after the treatment of GP and/or PNS. Conclusion: The distribution and expression of ERβ has been modulated under the administration of GP + PNS within the SH-SY5Y cells, whereas ERα has not. GP and PNS in combination may play an estrogenic-like effect with selectivity on ERβ modulation. Keywords: Geniposide, Panax notoginseng saponins, Estrogen receptor, SH-SY5Y cel

Contrasting characteristics, changes, and linkages of permafrost between the Arctic and the Third Pole

Permafrost degradation poses serious threats to both natural and human systems through its influence on ecological–hydrological processes, infrastructure stability, and the climate system. The Arctic and the Third Pole (Tibetan Plateau, TP hereafter) are the two northern regions on Earth with the most extensive permafrost areas. However, there is a lack of systematic comparisons of permafrost characteristics and its climate and eco-environment between these two regions and their susceptibility to disturbances. This study provides a comprehensive review of the climate, ecosystem characteristics, ground temperature, permafrost extent, and active-layer thickness, as well as the past and future changes in permafrost in the Arctic and the TP. The potential consequences associated with permafrost degradation are also examined. Lastly, possible connections between the two regions through land-ocean–atmosphere interactions are explored. Both regions have experienced dramatic warming in recent decades, characterized by Arctic amplification and elevation-dependent warming on the TP. Permafrost temperatures have increased more rapidly in the Arctic than on the TP, and will likely be reinforced under a future high emission scenario. Near-surface permafrost extents are projected to shrink in both regions in the coming decades, with a more dramatic decline in the TP. The active layer on the TP is thicker and has substantially deepened, and is projected to thicken more than in the Arctic. Widespread permafrost degradation increases geohazard risk and has already wielded considerable effects on the human and natural systems. Permafrost changes have also exerted a pronounced impact on the climate system through changes in permafrost carbon and land–atmosphere interactions. Future research should involve comparative studies of permafrost dynamics in both regions that integrate long-term observations, high-resolution satellite measurements, and advanced Earth System models, with emphasis on linkages between the two regions